I have just recently observed an odd behavior. I started with a score with three pages that already got lots of annotations and additional repeats. After a while I got to blow a solo and decided to add the changes of that part on a separate page. This page became page 4 first and I moved it to become page 3. After that all my annotations got lost. That is strange. Therefore I've gave it a try on a second score. On this score exactly the same behavior showed up.

Just came back form today's rehearsal. I had reentered all Annotations. And then they were duplicated. So the Annotations did disappear but they hadn't been lost an did reappear again. Curious thing, though.